1. Field of the Invention
This invention relates to a continuous process for the production of purified synthesis gas or hydrogen-rich gas with the concurrent production of a CO.sub.2 -rich gas suitable for injection into an underground oil reservoir to effect secondary recovery of oil.
2. Description of the Prior Art
Carbon dioxide has been removed from shifted synthesis gas by treating the synthesis gas with liquid solvent absorbents such as described in Industrial and Engineering Chemistry pages 37-43 July 1970, Vol. 62 No. 7 for the Rectisol Process (Lurgi-Linde) and the Purisol Process (Lurgi), and in Hydrocarbon Processing, page 100, April 1973, Vol. 52, No. 4 for the Selexol process (Allied Chemical Corporation). In said processes, nitrogen stripping gas is passed through the CO.sub.2 -saturated liquid solvent absorbent to regenerate the solvent. In such case, the CO.sub.2 off-gas from the stripping vessel would contain about 17 per cent nitrogen. In contrast, there is no stripping of solvents with nitrogen in the present invention. By the subject process there are produced a purified mixture of H.sub.2 and CO, a hydrogen-rich gas stream, and a CO.sub.2 -rich gas stream.
Carbon dioxide plus an inert gas is used for recovering oil from a spent oil reservoir by establishing miscibility conditions in the reservoir in coassigned U.S. Pat. No. 3,811,501.
Copper-liquor scrubbing of mixtures of H.sub.2 and CO to remove CO is described in Kirk-Othmer, Encyclopedia of Chemical Technology 2d. ed. Vol. 4. Interscience Publishers, New York, 1964.